Purpose/objectives: To review the mechanisms of multidrug resistance (MDR) in human cancer and the clinical use of MDR modulators to overcome or reverse P-glycoprotein (P-gp)-mediated MDR.
Data sources: Current literature, ongoing clinical trials, and clinical experience.
Data synthesis: Agents, such as valspodar, that block the activity of P-gp can reverse or overcome MDR caused by overexpression of P-gp. The MDR modulator valspodar (PSC 833; Novartis Pharmaceuticals Corporation, East Hanover, NJ) is examined as a model for establishing nursing guidelines for this new class of therapeutic agents.
Conclusions: The dose of some chemotherapy agents must be modified with concurrent valspodar administration. Studies examining the safety and efficacy of valspodar as a prototype of MDR modulators provide the basis for establishing nursing care guidelines.
Implications for nursing practice: Nursing care for the administration of valspodar includes understanding patient selection, criteria, dosing, and administration; side-effect management; patient monitoring and follow-up; and patient education.